The following evidence indicates that the proximal breakpoint of Df(2L)TW161 lies between RpL21 and RpL5. PCR analyses showed that RpL5, but not RpL21, is deleted in Df(2L)lt31 and Df(2L)lt64. These deletions were viable in combination with Df(2L)TW161, indicating that the deletion pairs do not overlap in the region of a vital gene. Df(2L)TW161 is associated with a Minute phenotype, but the haploinsufficient gene must map to a region that is not deleted by non-Minute deletions overlapping Df(2L)TW161. Currently, all but the most proximal region of Df(2L)TW161 is removed by other deletions. The region uniquely deleted by Df(2L)TW161 lies proximal to Df(2L)BSC151. The most likely candidate for the Minute gene is RpL21, which lies in the ~10 gene region between Df(2L)BSC151 and RpL5. Consequently, the proximal breakpoint of Df(2L)TW161 can be localized to  2L:22247111..22532279  (R6) based on the coordinates of the distal ends of RpL21 and RpL5.
The distal breakpoint of Df(2L)TW161 can be estimated as  2L:19795851..20061370  (R6) based on published results that say fs(2)ltoPP43 is not deleted and barr is deleted.